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Questions tagged [scanline]

47 questions
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1 answer

How to flood fill with Color of pattern image in swift?

I have achieved to flood fill on the close boundary with solid color. Now I am trying to fill close boundary with UIColor but it is pattern image color (Pattern color). I also try to get points of close area where i tap and fill that area with use…
Paresh Patel
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Fully expand this CSS inline-block div scan-line

I want this scan line effect to work properly. To reveal the text from left to right. As if the cathode-ray is burning it into the phosphors on the screen. The idea is to slide across black rows, that have a transparent tip. Here is a 80% working…
Cris Stringfellow
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How to implement the scanline access of TBitmap correctly?

I am trying to access the scanline of a Bitmap according to an article on Embarcadero. Using scanlines like for y := 0 to n do begin line := bitmap.scanline [y]; for x := 0 to n do line [x] := value; I have implemented before. I noticed that…
Arnold
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converting a PNGImage to grayscale using delphi

hi there here it is my code: procedure TForm4.Button1Click(Sender: TObject); var png: TPNGImage; data: PRGBQarray; p: ^tagRGBQuad; i, o: integer; begin png := TPNGImage.Create; try png.LoadFromFile('C:\Untitled.png'); for o := 1…
Javid
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Delphi TBitmap - why are Pixels and ScanLine different?

While using a 32 bit TBitmap, I switched from Canvas.Pixels to ScanLine. I then set the value to Red, only to find it was displayed as blue. Any idea why? Here's a code excerpt: procedure TForm1.FormPaint(Sender: TObject); var varBitmap: TBitmap; …
Jarno
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Make this retrocomputing scanline rock. Scan multiple lines in div is hard

Working fiddle be here: http://jsfiddle.net/WyXLB/1/ When a HTML element contains multiple lines of text, I want to scan over each one. At the moment, I am just scanning over the bounding rectangle of the entire element. Some code is : function…
Cris Stringfellow
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4 answers

How to get scanlines over background image in CSS

I have a full-page background image that I'd like to overlay scanlines over. I'm wanting to replicate the more traditional diagonal scanline effects that I grew up seeing in digital art of the noughties, such as implemented here in Bootstrap's…
Hashim Aziz
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3
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Scan Lines for Particle Filter with openGL

I am implementing a Particle Filter for a 3D cube tracking in C++. I faced a significant problem when assigning weights for the particles, because weights are based on the error in distance (in this case) between a sample point and a pixel…
VnC
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Algorithm: Create rooftop with maximum height

I have found this problem in a book and am trying desperately to solve it. The Question itself is: Create a rooftop (non-flat roofs) with the maximum height. The Walls are either in an angle of 90 degrees or parallel. My approach: I have all the…
Fabio Oesch
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Scanline fill algorithm using odd/parity rule

The question is this: Number the rows and columns in the following figure (outside the figure). Use these row column numbers to show how the scanline stack region filling algorithm would fill in this figure, starting at the pixel indicated. Show…
user1830954
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Pixel overlap with polygon: efficient (scanline-type) algorithm

Problem specification: I have a rectangular and uniformly spaced image of pixels with vertex coordinates (i,j), (i+1,j), (i, j+1), (i+1, j+1) [i=0,...,m-1; j=0,...,n-1] and a polygon P with vertex coordinates (x_1,y_1), ..., (x_n, y_n). Now I want…
Frederik Kaster
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Can scanline flood-fill optimization be extended to 3D?

I want to create a function that can quickly 'paint' a volume in a 3D binary array. The first approach I tried was extending a standard flood-fill algorithm into 3D, which was easy to do but I was interested in making it faster. I read into how to…
A B
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Implementing a scanline algorithm

I've been tasked with implementing a version of the scanline algorithm for an assignment. This program works by reading in a list of vertices and colors from a text file. Three vertices and three colors are popped from a queue at a time, then the…
user3308219
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delphi to lazarus - scanline

So, I have legacy code in Delphi and I wanted to try out that code in Lazarus. After making some changes the code compiled in Lazarus and I was good to go. However I have hit a problem that I could not get my head around. The original delphi code…
Dwight Schrute
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Scan Line Polygon Fill Algorithm

I am implementing a scan line based polygon fill algorithm. I know the general algorithm and I am now trying to implement it in C++. I need to implement the edge table an active edge list. I have made the active edge list a vector for easy inserting…
RXC
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